A sample of water from a water tank has a resistance of 100 $$\Omega$$ at 298 K, when placed in a conductivity cell of cell constant 0.2 $$\text{m}^{-1}$$. On dissolving 58.5 g of NaCl in the water tank, a sample of this solution gave a resistance of 40 $$\Omega$$. The molar conductivity of NaCl at this concentration is 10 $$\Omega^{-1}\text{m}^2\text{mol}^{-1}$$. The volume of water in the water tank is